Some New Pyrazolyl Pyrazolones and Cyanopyrazolyl Acrylates: Design, Synthesis and Biological Evaluation

Abstract

The present work is aimed to report several new synthetically and medicinally important pyrazole derivatives. Herein, a series of new 3‐amino‐4‐((3‐aryl‐1‐phenyl‐1H‐pyrazol‐4‐yl) methylene)‐1H‐pyrazol‐5(4H)‐ones (4) were synthesized by the reaction of ethyl 2‐cyano‐3‐(3‐aryl‐1‐phenyl‐1H‐pyrazol‐4‐yl) acrylates (3) and hydrazine hydrate in good yields. All the fourteen compounds (3 and 4) were evaluated for the in vitro antibacterial activity against, Staphylococcus aureus and Bacillus subtilis (Gram Positive), Escherichia coli and Pseudomonas aeruginosa (Gram negative) and the antifungal activity against Candida albicans and Saccharomyces cerevisiae. The tested compounds were found to be active against both the Gram positive strains.

4-Disubstituted Pyrazolin-3-Ones—Novel Class of Fungicides against Phytopathogenic Fungi

“…The history of the medical use of 4-unsubstituted pyrazolinones began as early as 1887 with the discovery of antipyrine (1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one), one of the first nonopioid analgesics and antipyretics. This discovery prompted the study of pyrazolone derivatives, including C4-monosubstituted pyrazolones, pyrazolone-based Schiff bases, and their metal complexes, which possess anti-inflammatory, antipyretic and analgesic [22,[25][26][27], antitumor/cytotoxic [22,25,[28][29][30], antimicrobial [22,25,[31][32][33], antioxidant [22,26], and protein denaturation inhibiting [27] activities. The interest of medicinal chemists to pyrazolones has been maintained and is increasing at the present time [22].…”